code: def _check_unexpected_columns(events):
      """Warn for each unexpected column that will not be used afterwards."""
      unexpected_columns = list(
          set(events.columns).difference(VALID_FIELDS)
      )
      if unexpected_columns:
          warnings.warn(
              "The following unexpected columns "
              "in events data will be ignored: "
              f"{', '.join(unexpected_columns)}"
          )
  
file_path: nilearn/nilearn/glm/first_level/experimental_paradigm.py
imports: import warnings
  import pandas
  from pandas.api.types import is_numeric_dtype
label_desc: Use image node_id 6 for calling a global function with example usage: _check_unexpected_columns(events) without return types